Filament winding apparatus



' Oct. 23, 1962 H. LOHEST FILAMENT WINDING APPARATUS 2 sheets. t 1

Filed July 2 I 1956 HANS HEsT 7 BY.- W WW vQQ/r ATT'YS Oct. 23, 1962 H. LOHEST 3,060,357

FILAMENT WINDING APPARATUS Filed July 26, 1956 2 Sheets-Sheet 2 FIGS FIG-6 HA NS LOH EST BYL.

ATT'YS rates The present invention relates, in general, to the winding and reeling of flexible material, and has more particular reference to the winding of thread and like filamentary material upon spools, bobbins and similar filament receivers, the invention pertaining specifically to the provision of improved winding mechanism having means for regulating the rate of turning movement of the winding reel in such fashion that, despite changes in the diameter of material as wound on the spool, the winding speed of the spool at all times corresponds with the rate of delivery of filamentary material thereto, wherey said filamentary material is wound upon the spool under substantially constant tension.

In winding devices of the character mentioned, it is conventional to provide a control device which reacts to Unite the changing size of the spool as filamentary material is wound thereon, or which reacts to the tension under which filamentary material is applied to the spool, and to employ the control device as a means for regulating the winding speed of the spool. Such devices do not react instantly, but have an inherent lag which can not be tolerated at high winding speeds which are now increasingly demanded in modern winding apparatus. Conventional speed regulating devices commonly apply undesirable tension upon the thread and thereby tend to cause thread breakage, especially where thin, light-weight filaments are involved.

Arrangements wherein the control devices are caused to react to the tension of the material being wound rather than to the winding diameter of the spool have the advantage of greater precision and also provide for adjusting the device to possible variations of tension in the material being wound. On the other hand, tension variations are often so weak, especially with thin filaments, that the variations in filament tension have to be transmitted to the control device in amplified form, thereby requiring electrical translation equipment for amplifying purposes. Control mechanisms of the sort heretofore known, which operate to switch on and off the spool driving motor, can not be used in high speed winding operations because of the violent disruptive sparking which develops at the make and break contacts of the associated switches.

An important object of the present invention is to provide improved control means for regulating the speed of a filament winding spool while avoiding the above noted shortcomings and disadvantages.

Another important object is to provide for controlling winding mechanism of the character mentioned by means of a driving motor energized at variable voltage, the potential of which fluctuates above and below the adjustable base potential of a principal power supply transformer through which operating energy is supplied to the driving motor; a further object being to provide means for increasing or decreasing the basic potential of energy supplied to the motor in accordance with variations in the tension of a filament being wound upon a spool driven by the motor.

Another important object is to utilize a control transformer for controlling the potential of electrical energy supplied through a principal transformer; a further object being to interconnect the transformers with a relative phase difference, the one with respect to the other, the

Patented Oct. 23, 1962 first difference being preferably of the order of ninety degrees.

Another important object is to control the delivery of electrical energy through a principal transformer by connecting the primary winding thereof with a fluctuating power source and by interconnecting the secondary winding of the transformer with that of a control transformer, the primary winding of which control transformer s energized from a power source, the phase of which is relatively displaced with respect to the energizing source of the principal transformer; a further object being to control the delivery of energy in the primary winding of the control transformer by means of an electronic switching device; a further object being to control the switching device in accordance with tension conditions prevailing in a filament as the same is windingly applied upon a spool or bobbin.

Since substantially all of the electrical energy required for actuating the spool driving motor is supplied through the principal transformer operating at its adjusted basic potential, the energy necessarily supplied through the control transformer is relatively small. The amount of energy required to be delivered through the adjusting transformer is relatively small, since only sufficient energy 1s needed to adjust motor speed above and below a normal operating spseed intermediate the maximum and minimum speeds at which the motor is required to operate.

Another important object of the present invention is to employ thyratron valves and appropriate valve actuating system for switching purposes. In this connection a pair of thyratrons connected in relatively parallel and reversed relation may be employed, whereby as a result of the inertia of the driving motor, a practically constant regulation is achieved. It is, however, also possible, by a special cooperating of the thread tension sensing pickup with a variable inductance or a variable condenser to control the thyratron valves in a manner to accomplish alteration of the potential delivered through the control transformer in exact accordance with the changes in tension in the filament. In the arrangement embodying thyrtarons in parallel and reversed relation, the control system may operate to permit thyratron ignition at ever constant instantaneous values of the fluctuating potential of the power source, whereby motor regulation may be accomplished by way of the control transformer during alternating periods of ignition and non-ignition of the thyratrons. Where a variable inductance or capacitance is employed in the control system, the moment of ignition of the thyratrons may be delayed in response to the operation of the tension sensing device so that the thyratrons operate to admit energy from the power main in fashion to accomplish regulation of the motor in response to the delayed ignition of the thyratrons.

The foregoing and numerous other objects, advantages and inherent functions of the invention will become apparent as the same is more fully understood from the following description which, taken in connection with the accompanying drawings, discloses a preferred embodiment of the invention.

Referring to the drawings:

FIG. 1 is a perspective view of filament winding apparatus embodying the present invention;

FIG. 2 is a diagrammatic view of a portion of the apparatus shown in FIG. 1;

FIG. 3 is an electrical wiring diagram of a motor control system embodying the invention;

FIGS. 4, 5 and 6 are wiring diagrams of electrical connections showing modified control systems embodying the invention; and

FIG. 7 shows a modification of the diagram illustrated in FIG. 5.

To illustrate the invention, the drawings show winding apparatus comprising a winding spindle 11 adapted to support and drivingly turn a Winding receiver R, such as a tube, mandrel, spool, reel or bobbin, thereon. Conventional bearing means of any suitable or preferred character may be employed for supporting the shaft for turning movement, as on a support frame or base 12. The base may also support an electrical motor 13 drivingly connected with the spindle 11 and operable to turn the receiver R at desired speed for winding a filament of the receiver. In accordance with the present invention, filamentary material, such as a thread, may be delivered from a supply source, such as a storage reel (not shown), or directly from a spinning machine, through a thread guide G for winding upon the receiver R as the same is turned on and by the spindle 1 1 driven by the motor 12. The guide G may be of any suitable or preferred character actuated by a conventional transfer device T driven by a motor M in order to cause the thread guide G to travel back and forth longitudinally of the receiver R at desired speed. The spindle and receiver driving motors are preferably caused to operate in synchronism; and, of course, the guide actuating device T, if desired, might be drivingly connected directly with the receiver driving motor 13. By using a separate motor M, however, the receiver driving motor 13 is not burdened with a guide driving load, and hence is entirely available for the task of driving the winding receiver. As a consequence, it can be of a relatively low power rating, and hence more sensitive to regulation in accordance with the teachings of the present invention.

The filament is preferably delivered upon the winding receiver at as nearly constant a rate of delivery speed as possible, the filament being delivered to the receiver past a sensing device S which may conveniently comprise an axially movable stem 14 carrying a grooved filament engaging head 15 and a spring 16 arranged to yieldingly urge the stem 14 in a direction to press the head 15 laterally against the filament as it passes to the receiver. The thrust of the spring may be adjusted to correspond with the filament tension under which it is desired to accomplish the winding operation. As the diameter of the wound filamentary material increases on the receiver R during a winding operation, it will be seen that the direction of the thread changes as it passes from the head of the sensing device S toward the receiver, the deflection angle A progressively increasing toward a maximum value, as clearly shown in FIG. 2 of the drawings. As a consequence, the pressure of the thread upon the sensing device progressively increases as the receiver becomes filled; and, even when the thread is under relatively slight tension, its force component upon the sensing device is sufiicient to activate the same.

The driving motor 13 may conveniently comprise an alternating current, short-circuit rotor-type motor with increased rotor resistance, or a Ferrari slip-bushing motor may be employed. In accordance with the teachings of the present invention, the motor 13 is electrically connected in a power supply system 17 including means adapted to supply electrical power in the motor energizing circuit 18 at a value which lies between the maximum and minimum power requirements of the motor, and means operable to increase and decrease the power delivered to the motor in accordance with the action of the sensing device under the influence of variant tension conditions in the filament as it is delivered for winding upon the receiver R. To these ends, the circuit 18 may include the secondary windings 19 and 26! of transformers 21 and 22, said secondary windings being interconnected in series relationship with the power receiving windings of the motor 13. The transformers 21 and 22, respectively, embody primary windings 23 and 24 energized from unlike phases of a multiphase alternating current power supply line L, the primary winding 24 being connected with the power supply line through switching means C controlled by the sensing device S. In multiple arrangements, in which a plurality of coil winding machines are disposed in side-by-side or adjacent relationship, the principal transformer 21 can be interconnected with the driving motors of each machine in order to supply them with power at the same basic potential.

The switching means C operates under the control of the sensing device S in order to control the supply of ener y to the motor energizing system 18 through the auxiliary or control transformer 22 in order to adjust the electrical energy in the supply circuit 18 at all times to that required to obtain the desired winding speed of the motor 13. in accordance with the present invention, the switching means C functions to accomplish both the choking of the basic potential down to a minimum operating value, as well as increasing potential in the motor energizing circuit up to maximum desired value. It will be seen from the foregoing that the principal transformer may be set to deliver power at a predetermined basic potential in the supply circuit 18 while the control trans former 22 may function to regulate the intensity, or duration, or number of successive power impulses required to be added or subtracted in order at all times to drive the motor 12 at desired speed; and it will be obvious that the foregoing is accomplished by virtue of the fact that energy supplied through the control transformer 22 is displaced as to phase with respect to that supplied through the principal transformer 21.

As shown more particularly in FIG. 4 of the drawings, the control system C may comprise a pair of thyratron valves 25 interconnected in relatively reversed, parallel relationship in series with the primary winding 24 of the transformer 22 between the conductors X and Y of a three-phase power supply line L, the primary winding of the principal transformer 21 being connected between the line conductor W and the grounded or neutral conductor Z. The control grids and cathodes of the thyratron valves 25 may be connected with suitable sources of unidirectional electrical energy for the purpose of actuating the valves, and a switch 26 may be provided for interconnecting the control grids of the valves in order to render the same electrically conductive, such switch being controllably connected with the stem 14- so that said switch is normally urged toward closed position by action of the spring 16 and will become open when tension in the filament P exceeds a selected value. So long as the switch 26 remains open the control transformer 22 will remain inactive, functioning merely as a choke in the circuit 18. Accordingly, reduced electric potential is Supplied to the motor 13, which, consequently, operates with considerable slippage until filament tension is relaxed, thereby allowing the spring 16 to close the switch 26. Upon activation of the thyratrons, power delivered through the control transformer is applied to modify or modulate that supplied in the circuit 18 through the prineipal transformer 21 in order to regulate the speed of the motor 13 in desired fashion. Accordingly, when the spring 16 causes the switch 26 to close, thereby igniting the thyratrons, the motor runs faster than when the switch is open. The sensitivity of the system is so good, even at high delivery speeds, that variation in thread tension is very limited. Because of the character of the control transformer, a relatively high potential can be employed in its primary circuit, whereby the current delivered through the thyratron valves may be of relatively low value so that the regulating impulse amplifier may have a low power rating.

It will be seen that the control system comprises auxiliary transformer means H, which may be energized from any suitable or convenient source, the primary winding of said auxiliary transformer means being not shown. If desired, the transformer means may comprise a pair of separate transformers, or a single transformer having separate secondary windings 27 and 27 may be employed. The transformer means H may also be employed, by means of secondary windings (not shown), for heating the cathodes of the thyratrons 25. The fluctuating energy produced in the windings 27 and 27 may be delivered through rectifiers R and R and stabilized by the condensers C1 and C1 as uni-directional electrical energy, which may be applied through voltage determining resistors R1, R-2, R-3, R-4, and R-l, R-2', R-3 and R4', to the grids of the thyratrons 25. Condensers C2 and C2 serve for the storage of the potential delivered on the grids of the thyratrons, said condensers C2 and C2 being provided mainly to suppress any waviness that may be present in the negative uni-directional potential applied upon the grids of the thyratrons, which are thus normally extinguished and in non-conductive condition when the switch 26 is open.

Upon closure of the switch 26 the resistors R-2, R-3, and R-2' and R-3' form voltage dividers, the grids of both thyratrons being connected through the grid resistances R-4 and R-4' at the center of such voltage divider. If it be assumed that the phase potential be positive with respect to the conductor Y of the three phase supply cable L, then current will flow from phase conductor X through the primary winding 24 of the transformer 22, thence through the resistors R2 and R-3, the closed switch 26, and thence through the resistors R-2' and R- 3' to phase conductor Y of the cable, because the grids of the thyratrons thus become electrically positive, thereby igniting the thyratron V-2, in so far as and so long as the cable conductor X is positive with respect to the conductor Y.

During the negative half wave of energy in the conductors X and Y, thyratron V-1 ignites in the same manner because its anode is then positive with respect to its cathode. During the negative half wave current flows from the phase conductor Y through the resistors R-2 and R-3, through the switch 26, and thence through the resistors R-2 and R-3 to the primary winding of the transformer 22, and thence back to phase conductor X. During the interval while the grids of the thyratrons are positive for the initiation of the ignition, the negative grid potential at condensers C1 and C1' is rendered ineffective by the high ohmic resistance of the resistors R-4 and R-4. Upon the opening of the switch 26, however, such negative grid potential immediately becomes effective for the extinguishment of the thyratrons.

As shown in FIG. 5, the system C may be arranged to control operation of the thyratron valves 25 by means of a variable condenser 26C which may be drivingly connected with the sensing device S. In such case, the thyratrons 25 may be interconnected between a pair of line conductors, such as the conductors X and Y of the power supply line L, the primary winding 24 of the control transformer being interconnected in series between one of the line conductors and the thyratrons. The two thyratron valves are alternately ignited by means of fluctuating potential applied in the grid circuits of the valves, such potential being provided by the secondary windings 31 and 32 of impulse transformers 33 and 34. The phase position of the alternating potential supplied to the grids of the thyratron valves may be displaced, say ninety degrees with respect to the potential applied on the anodes of the valves, as by means of a phase displacing bridge interconnected with the primary windings '35 and 36 of the impulse transformers, said bridge comprising a transformer 37 having a winding 38 connected on one side with the primary windings 35 and 36, the opposite side of the winding 38 being connected with the windings 35 and 36 through auxiliary thyratrons 39 and 40. Another winding 41 of the transformer 37 may be electrically connected through a resistance condenser network 42 with the control grids of the valves 39 and 40. A grid biasing potential for the auxiliary thyratrons 39 and 40 is applied across a resistor 43, the negative side of which is connected with a center tab on the winding 41, the positive side of the resistor 43 being connected with the cathodes of the auxiliary thyratrons through an adjustable resistor 44. The cathodes of the thyratrons 39 and 40 may also be electrically interconnected with the line conductor X.

The potential upon the grids of the thyratrons 39 and 40 may be altered as the result of the adjustment of the condenser 26C under the influence of the sensing device S. This can be accomplished by means of an electron valve 4 5, the anode of which may be connected to the positive side of a suitable source 46 of unidirectional power. The cathode of the tube may be connected, preferably through an adjustable resistance 47, and thence through the resistor 44 to the negative side of the power source 46. The valve 45 may be controlled by interconnecting a bridge 48 comprising four condensers between the oathode and control grid of the valve 45. The condenser bridge 48 may be energized from a suitable source 49' of high frequency energy in order to keep the capacitance and thereby the size of the bridge condensers as small as possible. One of the condensers of the bridge may comprise the condenser 26C which is connected with the sensing device S. Another of the condensers may be made adjustable.

When the bridge is adjusted to a desired setting, any unbalance thereof by action of the sensing device S on the condenser 26C will control the valve 45 to correspondingly change the potential applied across the resistor 44. The resistance 43 should be so large that the superimposed auxiliary alternating potentials from the phase brige extinguish the auxiliary thyratrons 39 and 40 whenever the sensing device is activated. In response to the operation of the sensing device, the effect of the auxiliary grid potential supplied across the resistor 43 is suppressed as the result of the application of an opposing potential across the resistor 44 by action of the valve 45 under the control of the condenser 26C. The sum of the potentials applied at the resistors 43 and 44 shifts the ignition level of the thyratrons 39 and 4t}, and hence shifts the ignition level of the main thyratron valves 25. As a consequence, greater or lesser energy is supplied through the primary winding of the control transformer 22.

Instead of the electron tube 45 in conjunction with a condenser bridge, the potential applied across the resistor 44 may be supplied under the control of a photoelectric cell or a photosensitive semi-conductor element connected across the resistor 44 in series with the power source 46. The photoelectric cell or photosensitive semi-conductor unit, as shown in FIG. 7, may be employed in conjunction with a small projection lamp as a light source, which may be shielded as by means of a shutter drivingly connected with the sensing device S in order to adjust the energy supplied from the power source 46 across the resistor 44. Numerous other known devices of conventional character may, of course, be employed for controlling the electrical energy applied across the resistor 44 in response to filament tension changes detected by the sensing device S.

As shown in FIG. '6 of the drawings, the thyratron valves 25 may be interconnected between a pair of line conductors, such as the conductors X and Y of the power supply line L, the primary winding 24 of the control transformer being connected in series between one of the line conductors and the thyratrons. The two thyratron valves are ignited alternately under the control of a variable reactance 26R which may be drivingly connected with the sensing device S. The valves 25 are thus ignited by fluctuating potential applied in the grid circuits of the valves, such potentials being provided by secondary windings '51 and 52 of a transformer 53 having a primary winding 54. The phase position of the fluctuating potential thus applied to the grids of the valves 25 may be displaced with respect to the potential applied on the anodes of the valves, as by means of a phase displacing bridge interconnected with the primary winding of the transformer 53, said bridge comprising a choke coil 55, the opposite sides of which are connected respectively with the line conductors X and Y.

One end of the coil 55 may be connected through an adjustable resistor 56 with one side of the transformer primary 54, the other side of said primary being connected with the coil 55 at a medial tap. The opposite end of the coil 55 may be connected with one side of the adjustable reactance 26R, the opposite side of said reactance being connected with the interconnected ends of the transformer primary 54 and the resistor 56. The phase angle of ignition of the valves 25 may be adjusted by means of the reactance coil within a range of nearly one hundred eighty degrees. Furthermore, the regulation of the fluctuating current flowing in the system is possible from a maximum value substantially all the way to a zero value.

The above described switching arrangements may, of course, be employed with direct current motors by introducing suitable converter means in the motor energizing circuit 18.

Since the energy requirements of the motor 13 are largely met by power delivered through the principal transformer 21 operating at substantially constant potential, the Work load through the control transformer 22 is relatively small. The range of regulation may be so arranged that the energy required at any time to reach either maximum and minimum rated capacity of the motor is of about the same magnitude. Energy required to adjust motor speed that must be provided by the regulating system is thus considerably smaller than is the case with conventional regulating mechanisms in which the basic potential corresponds either with the maximum or with minimum motor operating potential.

An important advantage of the present invention thus resides in the fact that the regulating devices may be made smaller and much more sensitive. Since only weak impulses are available from the filament for controlling the regulation of the motor, every reduction in size of the regulating mechanism is of importance in the interest of long life and economic operation of the mechanism. Furthermore, the driving motor may be made to operate at relatively higher than usual efllciency because a greater efiiciency is derived by supplying motor operating power through the principal transformer without very much energy being expended upon control through the phase shifted control transformer.

'It is thought that the invention and its numerous attendant advantages will be fully understood from the foregoing description, and it is obvious that numerous changes may be made in the form, construction and arrangement of the several parts without departing from the spirit or scope of the invention, or sacrificing any of its attendant advantages, the forms herein disclosed being preferred embodiments for the purpose of illustrating the invention.

The invention is hereby claimed as follows:

1. A speed regulating system for an electric motor comprising a circuit for delivering energizing power to the motor, a principal transformer connected in said circuit for applying therein essential electrical motor driving energy fluctuating at selected frequency, auxiliary transformer means connected in said circuit for applying therein, in addition to said essential motor driving energy supplied through the principal transformer, supplemental motor driving energy of fluctuating character and selected frequency, and selectively operable means connected with said auxiliary transformer means to control the same to operate selectively as a choke in said circuit and as a source of supplemental energy.

2. A speed regulating system as set forth in claim 1 wherein the regulated motor is drivingly connected with a filament winding receiver, and said selectively operable means is controllingly connected with sensing means reactive to tension variations in the filament being applied on the receiver, whereby to control filament winding speed in accordance with prevailing tension conditions in the filament.

3. A speed regulating system as set forth in claim 1 wherein the selectively operable means for controlling the auxiliary transformer means comprises an electronic switching system interconnected with the primary winding of said auxiliary transformer means.

4. A speed regulating system as set forth in claim 1 wherein the selectively operable means for controlling the auxiliary transformer means comprises an electronic switching system interconnected with the primary winding of said auxiliary transformer means, said electronic switching system embodying a pair of thyratron valves in relatively reversed, parallel relationship, and a switcl operable selectively to disable said thyratron valves and to condition the same for operation.

5. A speed regulating system as set forth in claim 1 wherein the selectively operable means for controlling the auxiliary transformer means comprises an electronic switching system interconnected with the primary winding of said auxiliary transformer means, said electronic switching system embodying a pair of thyratron valves in relatively reversed, parallel relationship, and a variable inductance interconnected with said thyratron valves for controlling the operation thereof.

'6. A speed regulating system as set forth in claim 1 wherein the selectively operable means for controlling the auxiliary transformer means comprises an electronic switching system interconnected with the primary winding of said auxiliary transformer means, said electronic switching system embodying a pair of thyratron valves in relatively reversed, parallel relationship, and a variable capacitance interconnected with said thyratron valves for controlling the operation thereof.

7. A speed regulating system for an induction motor comprising a circuit for delivering energizing power to the motor, main power supply means connected in said circuit for delivering therein essential electrical motor driving energy fluctuating at selected frequency, and auxiliary power supply means connected in said circuit, in series with said main power supply means, for applying in said circuit supplemental motor driving energy fluctuating at like frequency and displaced substantially 90 as to phase with respect to said essential motor driving energy, to thereby apply on the motor resultant motor driving energy that is out of phase with respect to said essential motor driving energy.

8. A speed regulating system for an induction motor comprising a circuit for delivering energizing power to the motor, a principal transformer connected in said circuit for delivering therein essential electrical motor driving energy fluctuating at selected frequency, and auxiliary transformer means connected in said circuit, in series with said principal transformer, for applying in said circuit supplemental motor driving energy fluctuating at like frequency and displaced substantially as to phase with respect to said essential motor driving energy, to thereby apply on the motor resultant motor driving energy that is out of phase with respect to said essential motor driving energy.

References Cited in the file of this patent UNITED STATES PATENTS 

